Residents in San Francisco had a rude awakening Saturday morning, thanks to the first ever tornado warning issued in the county and city. Tornado warnings have been issued just south in San Mateo ...

While rain looks to be the predominant type of precipitation, there appears to be a corridor for freezing rain. This is where warmer air runs up and over colder, denser air. Check out the graphics ...

Lake effect snow happens when relatively colder air moves over the unfrozen water of lakes. The colder air picks up moisture from the lakes, making it less dense and causing it to rise. Clouds and ...